Table II.

mechanisms of secondary hypocholesterolemia

In chronic illness:
- chronic exposure to IL-6 , IL-10 and TNF
- undernutrition due to anorexia
In critically ill patients:
- downregulation of hepatic synthesis, due to decreased production of cholesterol precursors.
- dilutional effects of fluid resuscitation
- loss of apoproteins in burns
- increased cholesterol catabolism
In cancer patients:
- elevated LDL receptor activity in malignant cells
- undernutrition due to anorexia
- effect of TNF
In anemia:
- increased cholesterol requirements by the proliferating erythoid cells
- elevated serum level of macrophage colony stimulating factor (M-CSF)
- hypersplenism
- autoantibodies against LDL causing an increased LDL catabolism
In thyrotoxicosis:
- enhanced LDL receptor-mediated catabolism of LDL particles
- increased bile excretion of cholesterol
- increased lipoprotein lipase, which catabolizes the triglyceride-rich lipoproteins
- increased LDL-receptor activity